Tubular conduits carrying pressurized fluids and gases are integral components in many automotive, machine tool, and household appliance applications and must be capable of being connected and disconnected quickly to facilitate repair or replacement of components in the system. Facilitating this connection/disconnection requirement, a number of tubular couplings have been developed as exemplified by the disclosures of U.S. Pat. No. 4,055,359 for "QUICKCONNECT TUBULAR COUPLINGS"; U.S. Pat. No. 3,924,885 for "HOSE COUPLING"; U.S. Pat. NO. 3,929,357 for "QUICK CONNECT COUPLING WITH TANDEM SNAP RIGS"; and U.S. Pat No. 3,453,005 for "QUICK-CONNECT SAFETY COUPLING".
These types of couplings represent relatively complex and expensive solutions to the problem of coupling tubular conduits. Prior art developments have established criteria by which the design of tubular couplings are often evaluated. These as listed in U.S. Pat. No. 4,055,359 include but are not limited to the following: (a) connect/disconnect assembly time must be significantly reduced over currently available fittings; (b) connection should be accomplished by a hand push; (c) the cost of components must be as low as possible and is to be achieved in part by the elimination of screw parts; (d) the coupling must weigh less than the current fittings available; (e) the "O" ring must be visible during connect/disconnect operations and secured in a groove to avoid warranty rework because of missing "O" rings; (f) less dependence on human factor during assembly thereby anticipating reliability improvements and warranty cost reduction; (g) coupling must have no rotary orientation requirement, thereby allowing hose assembly to neutralize all torsional stresses in the system; and (h) the design must have no threads, thereby eliminating cross threading.
Several prior art couplings in an attempt to meet other important design criteria have required the use of special tools for connecting or disconnecting couplings.
The requirement that disconnection cannot be accomplished without the use of specialized tools or destruction of the coupling is a major shortcoming of couplings heretofore devised.